2 * Copyright (C) 2015, 2016 ARM Ltd.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 #include <linux/uaccess.h>
18 #include <linux/interrupt.h>
19 #include <linux/cpu.h>
20 #include <linux/kvm_host.h>
21 #include <kvm/arm_vgic.h>
22 #include <asm/kvm_mmu.h>
26 * Initialization rules: there are multiple stages to the vgic
27 * initialization, both for the distributor and the CPU interfaces.
31 * - kvm_vgic_early_init(): initialization of static data that doesn't
32 * depend on any sizing information or emulation type. No allocation
35 * - vgic_init(): allocation and initialization of the generic data
36 * structures that depend on sizing information (number of CPUs,
37 * number of interrupts). Also initializes the vcpu specific data
38 * structures. Can be executed lazily for GICv2.
42 * - kvm_vgic_cpu_early_init(): initialization of static data that
43 * doesn't depend on any sizing information or emulation type. No
44 * allocation is allowed there.
50 * Those 2 functions should not be needed anymore but they
51 * still are called from arm.c
53 void kvm_vgic_early_init(struct kvm *kvm)
57 void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
64 * kvm_vgic_create: triggered by the instantiation of the VGIC device by
65 * user space, either through the legacy KVM_CREATE_IRQCHIP ioctl (v2 only)
66 * or through the generic KVM_CREATE_DEVICE API ioctl.
67 * irqchip_in_kernel() tells you if this function succeeded or not.
68 * @kvm: kvm struct pointer
69 * @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
71 int kvm_vgic_create(struct kvm *kvm, u32 type)
73 int i, vcpu_lock_idx = -1, ret;
74 struct kvm_vcpu *vcpu;
76 mutex_lock(&kvm->lock);
78 if (irqchip_in_kernel(kvm)) {
84 * This function is also called by the KVM_CREATE_IRQCHIP handler,
85 * which had no chance yet to check the availability of the GICv2
86 * emulation. So check this here again. KVM_CREATE_DEVICE does
87 * the proper checks already.
89 if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
90 !kvm_vgic_global_state.can_emulate_gicv2) {
96 * Any time a vcpu is run, vcpu_load is called which tries to grab the
97 * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
98 * that no other VCPUs are run while we create the vgic.
101 kvm_for_each_vcpu(i, vcpu, kvm) {
102 if (!mutex_trylock(&vcpu->mutex))
107 kvm_for_each_vcpu(i, vcpu, kvm) {
108 if (vcpu->arch.has_run_once)
113 if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
114 kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
116 kvm->arch.max_vcpus = VGIC_V3_MAX_CPUS;
118 if (atomic_read(&kvm->online_vcpus) > kvm->arch.max_vcpus) {
123 kvm->arch.vgic.in_kernel = true;
124 kvm->arch.vgic.vgic_model = type;
127 * kvm_vgic_global_state.vctrl_base is set on vgic probe (kvm_arch_init)
128 * it is stored in distributor struct for asm save/restore purpose
130 kvm->arch.vgic.vctrl_base = kvm_vgic_global_state.vctrl_base;
132 kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
133 kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
134 kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
137 for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
138 vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
139 mutex_unlock(&vcpu->mutex);
143 mutex_unlock(&kvm->lock);
150 * kvm_vgic_dist_init: initialize the dist data structures
151 * @kvm: kvm struct pointer
152 * @nr_spis: number of spis, frozen by caller
154 static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
156 struct vgic_dist *dist = &kvm->arch.vgic;
157 struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
160 dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL);
165 * In the following code we do not take the irq struct lock since
166 * no other action on irq structs can happen while the VGIC is
167 * not initialized yet:
168 * If someone wants to inject an interrupt or does a MMIO access, we
169 * require prior initialization in case of a virtual GICv3 or trigger
170 * initialization when using a virtual GICv2.
172 for (i = 0; i < nr_spis; i++) {
173 struct vgic_irq *irq = &dist->spis[i];
175 irq->intid = i + VGIC_NR_PRIVATE_IRQS;
176 INIT_LIST_HEAD(&irq->ap_list);
177 spin_lock_init(&irq->irq_lock);
179 irq->target_vcpu = vcpu0;
180 if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
189 * kvm_vgic_vcpu_init: initialize the vcpu data structures and
190 * enable the VCPU interface
191 * @vcpu: the VCPU which's VGIC should be initialized
193 static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
195 struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
198 INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
199 spin_lock_init(&vgic_cpu->ap_list_lock);
202 * Enable and configure all SGIs to be edge-triggered and
203 * configure all PPIs as level-triggered.
205 for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
206 struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
208 INIT_LIST_HEAD(&irq->ap_list);
209 spin_lock_init(&irq->irq_lock);
212 irq->target_vcpu = vcpu;
213 irq->targets = 1U << vcpu->vcpu_id;
214 if (vgic_irq_is_sgi(i)) {
217 irq->config = VGIC_CONFIG_EDGE;
220 irq->config = VGIC_CONFIG_LEVEL;
223 if (kvm_vgic_global_state.type == VGIC_V2)
224 vgic_v2_enable(vcpu);
226 vgic_v3_enable(vcpu);
230 * vgic_init: allocates and initializes dist and vcpu data structures
231 * depending on two dimensioning parameters:
232 * - the number of spis
233 * - the number of vcpus
234 * The function is generally called when nr_spis has been explicitly set
235 * by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
236 * vgic_initialized() returns true when this function has succeeded.
237 * Must be called with kvm->lock held!
239 int vgic_init(struct kvm *kvm)
241 struct vgic_dist *dist = &kvm->arch.vgic;
242 struct kvm_vcpu *vcpu;
245 if (vgic_initialized(kvm))
248 /* freeze the number of spis */
250 dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
252 ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
256 kvm_for_each_vcpu(i, vcpu, kvm)
257 kvm_vgic_vcpu_init(vcpu);
259 dist->initialized = true;
264 static void kvm_vgic_dist_destroy(struct kvm *kvm)
266 struct vgic_dist *dist = &kvm->arch.vgic;
268 mutex_lock(&kvm->lock);
271 dist->initialized = false;
274 kfree(dist->redist_iodevs);
277 mutex_unlock(&kvm->lock);
280 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
282 struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
284 INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
287 void kvm_vgic_destroy(struct kvm *kvm)
289 struct kvm_vcpu *vcpu;
292 kvm_vgic_dist_destroy(kvm);
294 kvm_for_each_vcpu(i, vcpu, kvm)
295 kvm_vgic_vcpu_destroy(vcpu);
299 * vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
300 * is a GICv2. A GICv3 must be explicitly initialized by the guest using the
301 * KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group.
302 * @kvm: kvm struct pointer
304 int vgic_lazy_init(struct kvm *kvm)
308 if (unlikely(!vgic_initialized(kvm))) {
310 * We only provide the automatic initialization of the VGIC
311 * for the legacy case of a GICv2. Any other type must
312 * be explicitly initialized once setup with the respective
315 if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
318 mutex_lock(&kvm->lock);
319 ret = vgic_init(kvm);
320 mutex_unlock(&kvm->lock);
326 /* RESOURCE MAPPING */
329 * Map the MMIO regions depending on the VGIC model exposed to the guest
330 * called on the first VCPU run.
331 * Also map the virtual CPU interface into the VM.
332 * v2/v3 derivatives call vgic_init if not already done.
333 * vgic_ready() returns true if this function has succeeded.
334 * @kvm: kvm struct pointer
336 int kvm_vgic_map_resources(struct kvm *kvm)
338 struct vgic_dist *dist = &kvm->arch.vgic;
341 mutex_lock(&kvm->lock);
342 if (!irqchip_in_kernel(kvm))
345 if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
346 ret = vgic_v2_map_resources(kvm);
348 ret = vgic_v3_map_resources(kvm);
350 mutex_unlock(&kvm->lock);
356 static void vgic_init_maintenance_interrupt(void *info)
358 enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
361 static int vgic_cpu_notify(struct notifier_block *self,
362 unsigned long action, void *cpu)
366 case CPU_STARTING_FROZEN:
367 vgic_init_maintenance_interrupt(NULL);
370 case CPU_DYING_FROZEN:
371 disable_percpu_irq(kvm_vgic_global_state.maint_irq);
378 static struct notifier_block vgic_cpu_nb = {
379 .notifier_call = vgic_cpu_notify,
382 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
385 * We cannot rely on the vgic maintenance interrupt to be
386 * delivered synchronously. This means we can only use it to
387 * exit the VM, and we perform the handling of EOIed
388 * interrupts on the exit path (see vgic_process_maintenance).
394 * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
395 * according to the host GIC model. Accordingly calls either
396 * vgic_v2/v3_probe which registers the KVM_DEVICE that can be
397 * instantiated by a guest later on .
399 int kvm_vgic_hyp_init(void)
401 const struct gic_kvm_info *gic_kvm_info;
404 gic_kvm_info = gic_get_kvm_info();
408 if (!gic_kvm_info->maint_irq) {
409 kvm_err("No vgic maintenance irq\n");
413 switch (gic_kvm_info->type) {
415 ret = vgic_v2_probe(gic_kvm_info);
418 ret = vgic_v3_probe(gic_kvm_info);
427 kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
428 ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
429 vgic_maintenance_handler,
430 "vgic", kvm_get_running_vcpus());
432 kvm_err("Cannot register interrupt %d\n",
433 kvm_vgic_global_state.maint_irq);
437 ret = __register_cpu_notifier(&vgic_cpu_nb);
439 kvm_err("Cannot register vgic CPU notifier\n");
443 on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
445 kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
449 free_percpu_irq(kvm_vgic_global_state.maint_irq,
450 kvm_get_running_vcpus());